Standard Bank remaining balance

Hi Hello peter my name is nonkululeko nokuthula Masango I'd like your assistance with regards the money that was left in my late mother's bank account which they promised to transfer it to us last year August till today we haven't heard anything from them, my worry is that the money used to be r6000 and something it keep decreasing why we don't know as we nolonger receiving bank statements or any documents from them I'm even thinking it's know on r3000 but even so we want.... Your assistance would be appreciated